Zoe-Elizabeth Sariyanni

Electromagnetically Induced Coherent Backscattering

We demonstrate a strong coherent backward wave oscillation using forward propagating fields only. This is achieved by applying laser fields to an ultradispersive medium with proper chosen detunings to excite a molecular vibrational coherence that corresponds to a backward propagating wave. The physics then has much in common with the propagation of ultraslow light. Applications to coherent scattering and remote sensing are discussed.

Generation and propagation of a resonant CARS signal from biomolecules: Application to dipicolinic acid

Abstract We develop a theoretical approach and perform simulations of coherent anti-Stokes Raman scattering (CARS) with ultrashort laser pulses. The signal is generated by biomolecules having subpicosecond dephasing times, from femtosecond pulses on exact resonance with the molecular transitions. All propagation effects are explicitly accounted for, including pump depletion, Raman amplification, parametric generation and pulse reshaping. Our model predicts that a measurable CARS signal can be generated by the dipicolinic acid biomolecule under realistic conditions.

Backward Raman amplification in the gas of rubidium dimers

We experimentally and theoretically study Raman scattering in rubidium (Rb) dimers. We observe the optical lines resulting from Raman scattering and demonstrate Raman amplification in the backward direction. A theoretical model has been developed to explain experimental the results.

Electromagnetically induced backscattering via slow light

We theoretically predict strong coherent scattering in the backward direction from forward propagating fields only. It is achieved by applying laser fields with proper chosen detunings and an approprate spatial phase to excite a molecular vibrational coherence that corresponds to a wave propagating backwards. The applications of the technique to coherent scattering and remote sensing are discussed.

Stimulated Raman scattering with shaped femtosecond pulses

We show that spectral hole refilling can be used to detect stimulated Raman scattering to determine vibrational frequency of molecules. The technique can be applied to spore detection and tissue microscopy.

Coherent backscattering in forward driven medium

We demonstrate how a strong coherent backward wave can be generated by forward propagating beams only. It is a dispersion effect resulting from probing a counter-propagating coherence grating by properly detuned fields.

Coherent Backscattering via Ultra Slow Light

A strong coherent backward wave oscillation using forward propagating fields only is achieved. This leads to controling phase-matching and having phase-matching simultaneously in forward and backward directions. It has applications to entangled photon state generation.

Femtosecond Nonlinear Spectroscopy on Biomolecules

We apply Coherent Anti-Stokes Raman Spectroscopy with femtosecond pulses on fast dephasing biomolecular media. We simulate the interaction, compare with the experiments and demonstrate its application as a real time detector for biochemical hazards.

Coherence preparation using simultaneous femtosecond laser pulses

We simulate the preparation of laser-induced vibrational coherence in the femtosecond time scale. By optimizing that coherence one can maximize the molecular CARS signal.

Observation of coherent anti-Stokes Raman scattering in phase-mismatched direction

We have experimentally demonstrated CARS scattering in the forward and backward directions. The signal observed in the backscattered is of the orders of magnitude stronger than would be expected.